SSBN-726 Ohio-Class FBM Submarines

Strategic deterrence has been the sole mission of the fleet ballistic missile submarine (SSBN) since its inception in 1960. The SSBN provides the nation's most survivable and enduring nuclear strike capability. The Ohio class submarine replaced aging fleet ballistic missile submarines built in the 1960s and is far more capable.

The TRIDENT II (D5) program achieved Initial Operational Capability (IOC) on 23 March 1990, when the USS TENNESSEE (SSBN 734) was deployed with 24 tactical D5 missiles. The TRIDENT II Strategic Weapon System (SWS) represents the sixth generation of the Navy's Fleet Ballistic Missile (FBM) Systems, which have served as significant deterrents to aggression and major war since POLARIS (A1) achieved IOC in 1960.

The Nuclear Posture Review (NPR), which was forwarded to Congress in December 2001, outlined the Strategic Submarine Force structure: 14 SSBNs outfitted with the TRIDENT II (D5) Strategic Weapon System in 2 oceans. In accordance with the NPR, the remaining four of the original eighteen TRIDENT SSBNs were converted to SSGNs. The four oldest of the OHIO Class submarines were selected for conversion to SSGNs because of their age and scheduled maintenance periods.

The Ohio-class submarines each carry 24 TRIDENT missiles. The ten Trident submarines in the Atlantic fleet stationed in Kings Bay, Georgia were initially equipped with the D-5 Trident II missile. The eight submarines in the Pacific stationed in Bangor, Washington, were initially equipped with the C-4 Trident I missile. In 1996 the Navy started to backfit submarines in the Pacific to carry the D-5 missile. Conversion of four of the C4 ships to carry the TRIDENT II/D5 missile began in FY 2000 and was completed in FY 2008.

To achieve an all D5 SSBN force, backfit of four of the submarines to the D5 Strategic Weapon System from the TRIDENT I (C4) Strategic Weapon System was initiated. The C4 SWS was retired in FY 2005. The TRIDENT SWS and support facilities were designed from the beginning to handle the newer and larger missile system with minimal impact and cost. By early 2003, two of the four SSBNs had completed backfit; one was fully operational and making deployments in the Pacific, and the other was finishing its final certification and testing. The second submarine was also homeported in the Pacific. The last two SSBNs started their backfit in FY 2005 and FY 2006.

The 2010 Nuclear Posture Review [NPR] concluded that ensuring a survivable U.S. response force requires continuous at-sea deployments of SSBNs in both the Atlantic and Pacific oceans, as well as the ability to surge additional submarines in crisis. To support this requirement, the United States currently had fourteen nuclear-capable Ohio-class SSBNs. By 2020, Ohio-class submarines will have been in service longer than any previous submarines. Therefore as a prudent hedge, the Navy will retain all 14 SSBNs for the near-term. Depending on future force structure assessments, and on how remaining SSBNs age in the coming years, the United States would consider reducing from 14 to 12 Ohio-class submarines in the second half of the decade. This decision will not affect the number of deployed nuclear warheads on SSBNs.

To maintain an at-sea presence for the long-term, the United States must continue development of a follow-on to the Ohioclass submarine. The first Ohio-class submarine retirement is planned for 2027. Since the lead times associated with designing, building, testing, and deploying new submarines are particularly long, the Secretary of Defense has directed the Navy to begin technology development of an SSBN replacement.

Today, there appears to be no credible near or mid-term threats to the survivability of U.S. SSBNs. However, given the stakes involved, the Department of Defense will continue a robust SSBN Security Program that aims to anticipate potential threats and develop appropriate countermeasures to protect current and future SSBNs.